Removal of gases from containers

ABSTRACT

Disclosed is a method of removing explosive or inflammable gases from a container which comprises continuously pumping into container containing liquid and highly explosive or highly inflammable gases, or such gases alone, a high expansion firefighting foam, and, when the available space within the container is full with such foam, continuously removing it at a rate corresponding to the inlet rate.

OR 3,757,865 5R Waited States Patent 1 flsmems 51 Sept. 11, 1973 [54]REMOVAL OF GASES FROM CONTAINERS 3,186,490 6/l965 Jamison et al. 169/2 RX [76} Inventor: Michael John Clements, FOREIGN PATENTS OR APPLICATIONS{9 Orient Drive, 825,444 12 1959 England 169/1 A Woolton, Liverpool,Lancashire, England Primary ExaminerM. Henson Wood, Jr. {22] Filed: AP28 1971 Assistant ExaminerA. Kashnikow Appl. No.: 138,322

AttorneySalter & Michaelson [5 7 ABSTRACT Disclosed is a method ofremoving explosive or inflammable gases from a container which comprisescontinuously pumping into container containing liquid and highlyexplosive or highly inflammable gases, or such gases alone, a highexpansion fire-fighting foam, and, when the available space within thecontainer is full with such foam, continuously removing it at a ratecorresponding to the inlet rate.

1 Claim, No Drawings.

REMOVAL OF GASES FROM CONTAINERS This invention concerns enclosures orcontainers containing highly explosive or inflammable gases.

There are many instances in industry and commerce where the presence ofhighly explosive or inflammable gases in enclosures or containersconstitutes a considerable explosion and fire hazard. This is especiallyso in many ships which have so-called slop tanks in which are collectedwaste liquids such as bilge water, crude oil and the like. Such sloptanks tend to become full, in the space above the liquid, with highlyinflammable gases and these are naturally highly susceptible toignition, especially, for example, when cargo is beingdischarged andsparks might be caused.

The object of the present invention is to provide a method of removingexplosive or inflammable gases from enclosures or containers in a mannerwhich wil substantially reduce, if not eliminate, explosion and firehazards.

According to the present invention I continuously pump into an enclosureor container containing liquid and highly explosive or highlyinflammable gases or such gases alone, a high expansion fire-fightingfoam, and, when the available space within the container is full withsuch foam, continuously remove it at a rate corresponding to the inletrate. We have found that the inflammable gases become entrained in thefoam and are thereby removed in a safe way from the enclosure orcontainer.

In practising one particular embodiment of the invention, when a ship isnewly docked high expansion firefighting foam (such as that commerciallyavailable under the designation TOTAL high expansion foam) isimmediately pumped into each slop tank through a suitably disposedaperture and when the space above the liquid therein is filled with thefoam, the foam with the inflammable gases entrained therein iscontinuously forced out through another suitably disposed aperture at arate which will ensure that the space above the liquid in the slop tankis always filled with foam. The foam emerging from the tank may bedisposed of in any suitable way. After cargo has been discharged and theship has left port the supply of foam to the tank now sealed is stopped.

In this way fire and explosion hazards in the slop tanks of ships aresubstantially eliminated. We believe, surprisingly,'that the foam beingdrawn off from the slop tank and in which the inflammable gases areentrained will not be readily susceptible to ignition and therefore thepossibility of flash back into the slop tank is also excluded.

The invention of course is not limited to use in connection with shipslop tanks but is equally applicable to any container in which there isan accumulation or a continuing accumulation of highly inflammablegases.

I claim:

1.- A method of preventing an explosion or fire from occurring in anenclosed container which holds a material from which explosive orinflammable gases may emanate, comprising the steps of pumping into saidcontainer an expansion, fire-fighting foam until the available spacewithin the container is substantially filled with said foam, and theexplosive or inflammable gases are entrained in said foam, andthereafter continuously pumping said foam into said container whileforcing the foam therein in which the explosive or inflammable gases areentrained outwardly of said container by way of an aperature formed insaid container, and at a rate that insures that the available space inthe container is always filled with said foam,'wherein the fire and/orexplosion hazard in said container is eliminated.

1. A method of preventing an explosion or fire from occurring in anenclosed container which holds a material from which explosive orinflammable gases may emanate, comprising the steps of pumping into saidcontainer an expansion, fire-fighting foam until the available spacewithin the container is substAntially filled with said foam, and theexplosive or inflammable gases are entrained in said foam, andthereafter continuously pumping said foam into said container whileforcing the foam therein in which the explosive or inflammable gases areentrained outwardly of said container by way of an aperature formed insaid container, and at a rate that insures that the available space inthe container is always filled with said foam, wherein the fire and/orexplosion hazard in said container is eliminated.